A conventional starter for starting a vehicle engine is designed as shown in FIG. 1
More specifically, the conventional starter device 1, as shown in FIG. 1, comprises: a DC motor 2; an over-running clutch 4 slidably mounted on the output rotary shaft 3 of the motor; an electromagnetic switch 6 provided beside the DC motor 2; and a shift lever 10 having one end engaged with a hook 8 coupled to the plunger 7 of the electromagnetic switch 6 and the other end engaged with the cylindrical rear end portion 9 of the over-running clutch 4 so as to slide the over-running clutch 4 on the output rotary shaft 3.
The electromagnetic switch 6 for operating the shift lever 10 has a cylindrical outer frame 11 which has a wall 11a at one end. The aforementioned plunger 7 is inserted into the end wall 11a. A stationary iron core 12 is disposed at the other end of the outer frame 11 in such a manner as to confront with the plunger 7. The iron core 12 has an end wall which is fixedly fitted in the rear end portion of the outer frame 11, thus forming a frame together with the outer frame 11. A coil bobbin 13 is accommodated in the frame thus formed. An exciting coil 14 is wound on the coil bobbin 13. A return spring 15 is interposed between the iron core 12 and the plunger 7. The iron core 12 has a central through-hole, into which a rod 16 is slidably inserted in such a manner that its one end portion (or front end portion) is extended from the iron core 12 towards the plunger 7. The other end portion (or rear end portion) of the rod 16 supports a movable contact 17.
The starter further comprises: a carrier rod 18 for returning the rod to a predetermined position; a cap 19 made of resin; and a terminal bolt 20 embedded in the cap 19 so that its inner end serves as a stationary contact with which the movable contact 17 is brought into contact. A magnet 25 connected at the base of the DC motor 2 and a brush box assembly 26 placed in the rear end of the starter motor as protecting device.
The plunger 7 is inserted into the central opening formed in the end wall 11a of the outer frame 11, and it is moved along the central axis of the coil bobbin 13 towards the iron core 12. The plunger 7 has a recess which is opened axially outward. The above-described connecting rod 8 is in the form of a piston and has a flange at the rear end. The connecting rod 8 is slid ably inserted into the recess of the plunger 7 and is extended outside passing through the central hole that is formed in a holder 21, which closes the open end of the recess of the plunger 7. The outer end portion of the connecting rod 8 is engaged with the upper end of the shift lever 10. Inside the recess of the plunger 7, a cylindrically coiled spring, namely, a compression spring 22 is interposed between the holder 21 and the flange of connecting rod 8.
The operation of the conventional starter thus constructed will be described in brief.
When the key switch of the vehicle is turned on, the exciting coil 14 of the electro-magnetic switch 6 is energized so that the plunger 7 is moved towards the iron core 12. As a result, the shift lever 10 is turned, whereby the over-running clutch 4 and the pinion 5 integral with the clutch inner portion are slid on the output rotary shaft 3. In this operation, when the pinion 5 abuts against the side of the engine ring gear, the turning of the shift lever 10 is stopped while the plunger 7 continues to move towards the iron core, the compression spring 22 is compressed, so that the pinion is pushed against the engine ring gear through the shift lever 10.
As the plunger 7 pushes the rod, the movable contact 17 is brought into contact with the stationary contact, so that the DC motor 2 is energized. As a result, as soon as the pinion 5 is rotated, it is engaged with the engine ring gear by the elastic force of the compression spring 22.
FIG. 2 describes about the lever 10 in the engaged position with plunger 7 in the solenoid assembly, by this the contactor get connected with the battery terminal. Through this conventional setup the coil energise and the motor starts to crank the vehicle, this operation takes simultaneously.
The conventional solenoid assembly is shown in the FIG. 3 consist of plunger assembly 31 which connects with frame 33 by means of return spring 32. The primary and secondary coils 35 with two leads rounded on a bobbin 34, the plunger strip 36 connects the bobbin and the contact plate 38 though the over travel spring and the other end of the contact plate is connected to the contact return spring 39. The whole solenoid 6 is closed through the cap assembly 41 with a gasket 40 to avoid damages
To reduce damage to the pinion, a no-restarting period during which restart is prohibited is required to be set when the engine is rotating in the negative direction. However, as a result of the no-restarting period being set, prompt restarting of the engine becomes difficult to achieve. Usability of the idle stop apparatus is degraded.